Hi, I'd like to know the purpose of MOS (maintenance override switch). A

Hi,
I'd like to know the purpose of MOS (maintenance override
switch). At site, these switches are installed in a
stanchion with the transmitter (connected to ESD). thank
you.

Question Posted / gk3000

3 Answers
34480 Views
Adani, Adani Wilmar, I also Faced
E-Mail Answers

Answers were Sorted based on User's Feedback

Hi, I'd like to know the purpose of MOS (maintenance override switch). At site, these switch..

Answer / wael salah

maintenance override function is used for bypassing shutdown
processing so that it is not executed by safety logic during
partial maintenance such as specific input.Creating bypass
logic using a dedicated override allows the (HIS) to safely
perform maintenance override for SCS (system control station)
However Maintenance override can not executed from the HIS
unless this switch is in the permission status.

Is This Answer Correct ?

22 Yes

0 No

Hi, I'd like to know the purpose of MOS (maintenance override switch). At site, these switch..

Answer / seba

MOS is used for enabling /disabling (permision to bypasing
shutdown signal from ESD system.once it enabled you can
overide perticular loop or swtich or function block.
MOS is installed normally on DCS and activating by DCS
operator or concerned engineer for allowing maintenance
technician to perform calibration or replacement of faulty
switches and transmitters.
sebalukose@gmail.com

Is This Answer Correct ?

20 Yes

2 No

Hi, I'd like to know the purpose of MOS (maintenance override switch). At site, these switch..

Answer / winter r

I want a example defeat of control sheet about when
something is verride .

Is This Answer Correct ?

1 Yes

2 No

Post New Answer

More Instrumentation Interview Questions

how to calibrate load cell

0 Answers Siemens,

What is the difference between HMI,SCADA and MMI,not abbrevation?

7 Answers HCL,

What are different types of control valves?

0 Answers

1. What means HART communicator / where it is used / how to use it? 2. Types of Thermocouples and its temperature ranges / output of thermocouple? 3. Types of RTDs and its temperature ranges / output of RTD? 4. Idea about Temperature Transmitters? 5. Difference between Analog and Digital signals? 6. Difference between “2 wire” and “4 wire” system / instruments? 7. Difference between “Potential” and “Potential free” contact? 8. Types of flow meters / transmitters? 9. Types of level transmitters? 10. Difference between “Power/Control” cable and “Instrument” cable? 11. What means “shield” and “screen” in cables / how it is useful? 12. Draw a schematic of closed loop circuit of flow / level / pressure / temperature? 13. Idea about calibration of Control valve / positioned / I/P? 14. How to bypass a digital/analog signal in PLC/DCS by hardwire and software?

6 Answers JSL,

When cryogenic control valve will be applied?

1 Answers

How does a strain gauge measure pressure?

2 Answers

WHAT IS DIFFERANCE BETWEEN INSTRUMENT AND EQUIPMENT

1 Answers Lupin,

Difference HAZOP and HIRA

1 Answers

How we are deciding while programming in pid controller , What we are using heating or cooling.

1 Answers

What is hp & mp seperator .& what is its working principle ?

0 Answers Chevron,

installation process of orifice,a question asked for confusion creation in interview by BARC 1.if orifice is tightly fitted with pipe ,it will act like venturi 2.if orifice is left hanging in between liquid it will not create the pressure difference exactly,

0 Answers BARC,

in mass flow meter what is drive friquancy ?

0 Answers

For more Instrumentation Interview Questions Click Here